Windbreaks for Farms and Acreages
Note to media editors:
Garden Column for the week of Jan. 13, 2006.
By Paul Wray
Iowa State University Extension
Windbreaks should be an integral part of the farm and acreage landscape. Farmstead windbreaks and field shelterbelts have positive effects on several environmental conditions including reductions in wind erosion, reducing chill factors during the winter months, reduction in drying of plants during the summer, improved heat budgets for houses and buildings, improved feed conversion of feedlot animals, improved wildlife habitat and property value enhancement through beautification.
Some general rules to follow for farmstead windbreaks include: Plant at least two rows of conifers on the north and west side of the farmstead; to reduce snow drift problems, leave 50 to 100 feet between the windbreak and critical farmstead areas; plant at least two different species of conifers; choose species which are best adapted to your site. For some sites consider a strip of prairie or warm season grasses for both snow capture and wildlife habitat.
Conifer species commonly used for farmstead windbreaks include white and red pines; white, Black Hills, Norway and blue spruces; white fir, eastern red cedar and arborvitae. Common shrub species include ninebark, dogwoods, lilac, hazelnut, spirea and viburnums. Some of the large hardwood trees used include silver maple, ashes, hackberry and cottonwoods. Try to match the species to planting site. Assistance is available from your local Natural Resource Conservation Service (NRCS) office. NRCS staff have recently developed a soil suitability rating for trees and soils to ensure better tree performance. It can be accessed at: http://www.ia.nrcs.usda.gov/plants.html
The minimum windbreak in Iowa consists of two rows of conifers and a row of shrubs usually planted on the outer edge of the windbreak. Protection will be increased with additional rows of trees. A better windbreak will consists of three to six rows of conifers, two rows of shrubs and one to two rows of large hardwood trees. Spacing is usually 15 to 20 feet between rows and between trees within the row. Smaller conifers (arborvitae and eastern red cedar) may be planted as close as 10 to 12 feet between trees within a row. Large hardwood trees are typically planted 12 to 20 feet between trees. Shrubs spacing is variable depending on the species but usually varies from three to six feet.
For more information contact forestry extension or your ISU Extension County office and ask for Farmstead Windbreaks: Planning, (PM 1716) and Farmstead Windbreaks: Establishment, Care and Maintenance, (PM 1717.) These also can ordered or downloaded at www.extension.iastate.edu/store/
Paul Wray, Forestry, (515) 294-1168, firstname.lastname@example.org
Jean McGuire, Continuing Education and Communication Services, (515) 294-7033, email@example.com
There are two high resolution photos available for use with this week's column:
Windbreak with prairie grass buffer, [PrairieWind11306.jpg] 484 KB
New windbreak, [NewWind11306.jpg] 432 KB